Photoresist composition and method of forming photoresist pattern

ABSTRACT

A method of forming a photoresist pattern includes forming a protective layer over a photoresist layer formed on a substrate, and selectively exposing the protective layer and the photoresist layer to actinic radiation. The protective layer and the photoresist layer are developed to form a pattern in the photoresist layer, and the protective layer is removed. The protective layer includes a polymer having pendant fluorocarbon groups and pendant acid leaving groups.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. application Ser.No. 16/163,425, filed Oct. 17, 2018, now U.S. Pat. No. 11,016,386, whichclaims priority to U.S. Provisional Patent Application No. 62/685,721filed Jun. 15, 2018, the entire disclosures of each of which areincorporated herein by reference.

TECHNICAL FIELD

The disclosure relates to photoresist compositions and methods offorming photoresist patterns in a semiconductor manufacturing processes.

BACKGROUND

As consumer devices have gotten smaller and smaller in response toconsumer demand, the individual components of these devices havenecessarily decreased in size as well. Semiconductor devices, which makeup a major component of devices such as mobile phones, computer tablets,and the like, have been pressured to become smaller and smaller, with acorresponding pressure on the individual devices (e.g., transistors,resistors, capacitors, etc.) within the semiconductor devices to also bereduced in size.

One enabling technology that is used in the manufacturing processes ofsemiconductor devices is the use of photosensitive materials. Suchmaterials are applied to a surface and then exposed to an energy thathas itself been patterned. Such an exposure modifies the chemical andphysical properties of the exposed regions of the photosensitivematerial. This modification, along with the lack of modification inregions of the photosensitive that were not exposed, can be exploited toremove one region without removing the other.

However, as the size of individual devices has decreased, processwindows for photolithographic processing has become tighter and tighter.As such, advances in the field of photolithographic processing arenecessary to maintain the ability to scale down the devices, and furtherimprovements are needed in order to meet the desired design criteriasuch that the march towards smaller and smaller components may bemaintained.

Extreme ultraviolet lithography (EUVL) has been developed to formsmaller semiconductor device feature size and increase device density ona semiconductor wafer. As device features shrink the elimination ofdefects becomes more critical. Defects may be formed by the absorptionof contaminants, such as particles, moisture, and ammonia in aphotoresist during processing.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 illustrates a process flow according to embodiments of thedisclosure.

FIGS. 2A and 2B show process stages of sequential operations accordingto an embodiment of the disclosure.

FIGS. 3A, 3B, 3C, and 3D show process stages of sequential operationsaccording to an embodiment of the disclosure.

FIG. 4 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 5 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 6A and 6B show a process stage of a sequential operation accordingto embodiments of the disclosure. FIGS. 6C and 6D show a process stageof a sequential operation according to other embodiments of thedisclosure.

FIG. 7 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 8 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 9 shows polymer resins according to embodiments of the disclosure.

FIG. 10 shows polymer resins according to embodiments of the disclosure.

FIG. 11 illustrates a process flow according to embodiments of thedisclosure.

FIG. 12 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 13 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 14 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 15 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 16 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 17 shows a process stage of a sequential operation according to anembodiment of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the disclosure. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

FIG. 1 illustrates a process flow 100 of manufacturing a semiconductordevice according to embodiments of the disclosure. A photoresist iscoated on a surface of a layer to be patterned or a substrate 10 inoperation S110, in some embodiments, to form a photoresist layer 15, asshown in FIGS. 2A and 2B. The photoresist includes a protective polymer20 that forms a protective layer over the photoresist layer 15, as shownin FIG. 2B. The photoresist/protective polymer mixture is dispensed froma dispenser 25. While the photoresist/protective polymer mixture isapplied or immediately thereafter, the substrate 10 is rotated. Whilethe substrate is rotated, the protective polymer separates from thephotoresist composition and forms a protective layer 20 over thephotoresist layer 15. In some embodiments, the protective polymerseparates from the mixture because of its hydrophobicity relative to thephotoresist. The protective layer 20 prevents contaminants, includingparticles, moisture, and ammonia, from being absorbed into orimpregnating the photoresist layer 15.

Then the photoresist layer 15 and protective layer 20 undergo a firstbaking operation to evaporate solvents in the photoresist composition insome embodiments. The photoresist layer 15 and protective layer 20 arebaked at a temperature and time sufficient to cure and dry thephotoresist layer 15 and protective layer 20. In some embodiments, thelayers are heated to a temperature of about 40° C. and 200° C. for about10 seconds to about 10 minutes.

In other embodiments, the photoresist 15 is coated on a surface of alayer to be patterned or a substrate 10 in operation S110 to form aphotoresist layer 15, as shown in FIGS. 3A and 3B. As explained inreference to FIG. 2A, the photoresist is dispensed from a dispenser 25.While the photoresist is applied or immediately thereafter, thesubstrate 10 is rotated. Then the photoresist layer 15 undergoes a firstbaking operation to evaporate solvents in the photoresist composition insome embodiments. In some embodiments, the photoresist layer 15 isheated to a temperature of about 40° C. and 200° C. for about 10 secondsto about 10 minutes.

After the first baking operation, a protective layer 20 is coated on thephotoresist layer 15. As shown in FIGS. 3C and 3D. The protective layer20 is a protective polymer composition 20 dispensed from a dispenser 27,as shown in FIG. 3C. While the protective polymer composition is appliedor immediately thereafter, the substrate 10 is rotated.

Then the protective layer 20 undergoes a baking operation to evaporatesolvents in the protective polymer composition in some embodiments. Theprotective layer 20 is baked at a temperature and time sufficient tocure and dry the protective layer 20. In some embodiments, thephotoresist layer is heated to a temperature of about 40° C. and 200° C.for about 10 seconds to about 10 minutes.

After the photoresist and protective layers 15, 20 undergo the bakingoperation, the photoresist layer 15 and protective layer 20 areselectively exposed to actinic radiation 45 (see FIG. 4) in operationS130. In some embodiments, the ultraviolet radiation is deep ultravioletradiation. In some embodiments, the ultraviolet radiation is extremeultraviolet (EUV) radiation. In some embodiments, the radiation is anelectron beam. In some embodiments, the thickness of the protectivelayer 20 is sufficiently thin so that the protective layer 20 does notadversely affect the exposure of the photoresist layer 15 to theradiation 45. In some embodiments, the protective layer has a thicknessranging from about 0.1 nm to about 20 nm. In some embodiments, thethickness of the protective layer ranges from about 1 nm to about 15 nm.In some embodiments, the contact angle of the protective layer to wateris greater than 75°.

As shown in FIG. 4, the exposure radiation 45 passes through a photomask30 before irradiating the protective layer 20 and the photoresist layer15 in some embodiments. In some embodiments, the photomask has a patternto be replicated in the protective layer 20 and the photoresist layer15. The pattern is formed by an opaque pattern 35 on photomask substrate40, in some embodiments. The opaque pattern 35 may be formed by amaterial opaque to ultraviolet radiation, such as chromium, while thephotomask substrate 40 is formed of a material that is transparent toultraviolet radiation, such as fused quartz.

The regions 50, 50′ of the photoresist layer and the protective layerexposed to radiation undergo a chemical reaction thereby changing theirsolubility in a subsequently applied developer relative to the regions52, 52′ of the photoresist layer and protective layer not exposed toradiation. In some embodiments, the portions 50, 50′ of the photoresistlayer and protective layer exposed to radiation undergo a crosslinkingreaction.

Next, the photoresist layer 15 and protective layer 20 undergo apost-exposure bake in operation S140. In some embodiments, thephotoresist layer 15 and protective layer 20 are heated to a temperatureof about 50° C. and 160° C. for about 20 seconds to about 120 seconds.The post-exposure baking may be used in order to assist in thegenerating, dispersing, and reacting of an acid/base/free radicalgenerated from the impingement of the radiation 45 upon the protectivelayer 20 or photoresist layer 15 during the exposure. Such thermalassistance helps to create or enhance chemical reactions, which generatechemical differences between the exposed regions 50, 50′ and theunexposed regions 52, 52′ within the photoresist layer or protectivelayer. These chemical differences also cause differences in thesolubility between the exposed region 50 and the unexposed region 52.

The selectively exposed protective layer and photoresist layer issubsequently developed by applying a developer to the selectivelyexposed photoresist layer in operation S150. As shown in FIG. 5, adeveloper 57 is supplied from a dispenser 62 to the protective layer 20and the photoresist layer 15. In some embodiments the exposed portions50′ of the protective layer remain on the photoresist layer 15 and theunexposed portions are removed during development as shown in FIG. 6A.In some embodiments, the exposed portions 50′ of the protective layer 20remain on the exposed portions of the photoresist layer 50 afterdevelopment, as shown in FIG. 6B. The remaining portions 50′ of theprotective layer are subsequently removed using a suitable stripperafter developing the photoresist layer 15. In some embodiments, a firstdeveloper is used to develop the protective layer 20 and then a second,different developer is used to develop the photoresist layer 15.

In other embodiments, the exposed portions 50′ of the protective layerare removed during development and the unexposed portions 52′ remain onthe photoresist layer 15 after development, as shown in FIG. 6C. Upondevelopment, the exposed portions of the photoresist layer 15 areremoved exposing the layer to be patterned or substrate 10, as shown inFIG. 6D. In some embodiments, a first developer is used to develop theprotective layer 20 and then a second, different developer is used todevelop the photoresist layer 15.

The protective layer 20 remaining over the photoresist layer 15 in FIG.6B is subsequently removed using a suitable stripper to expose the uppersurface of the photoresist layer 15, as shown in FIG. 7.

In some embodiments, the pattern of openings 55 in the photoresist layer15 are extended into the layer to be patterned or substrate 10 to createa pattern of openings 55′ in the substrate 10, thereby transferring thepattern in the photoresist layer 15 into the substrate 10, as shown inFIG. 8. The pattern is extended into the substrate by etching, using oneor more suitable etchants. The exposed portion 50 of the photoresistlayer is at least partially removed during the etching operation in someembodiments. In other embodiments, the exposed photoresist layer 50 isremoved after etching the layer to be patterned or substrate 10 by usinga suitable photoresist stripper solvent or by a photoresist ashingoperation.

In some embodiments, the substrate 10 includes a single crystallinesemiconductor layer on at least it surface portion. The substrate 10 mayinclude a single crystalline semiconductor material such as, but notlimited to Si, Ge, SiGe, GaAs, InSb, GaP, GaSb, InAlAs, InGaAs, GaSbP,GaAsSb and InP. In some embodiments, the substrate 10 is a silicon layerof an SOI (silicon-on insulator) substrate. In certain embodiments, thesubstrate 10 is made of crystalline Si.

The substrate 10 may include in its surface region, one or more bufferlayers (not shown). The buffer layers can serve to gradually change thelattice constant from that of the substrate to that of subsequentlyformed source/drain regions. The buffer layers may be formed fromepitaxially grown single crystalline semiconductor materials such as,but not limited to Si, Ge, GeSn, SiGe, GaAs, InSb, GaP, GaSb, InAlAs,InGaAs, GaSbP, GaAsSb, GaN, GaP, and InP. In an embodiment, the silicongermanium (SiGe) buffer layer is epitaxially grown on the siliconsubstrate 10. The germanium concentration of the SiGe buffer layers mayincrease from 30 atomic % for the bottom-most buffer layer to 70 atomic% for the top-most buffer layer.

In some embodiments, the substrate 10 includes at least one metal, metalalloy, and metal/nitride/sulfide/oxide/silicide having the formulaMX_(a), where M is a metal and X is N, S, Se, O, Si, and a is from about0.4 to about 2.5. In some embodiments, the substrate 10 includestitanium, aluminum, cobalt, ruthenium, titanium nitride, tungstennitride, tantalum nitride, and combinations thereof.

In some embodiments, the substrate 10 includes a dielectric having atleast silicon, metal oxide, and metal nitride of the formula MX_(b),where M is a metal or Si, X is N or O, and b ranges from about 0.4 toabout 2.5. Ti, Al, Hf, Zr, and La are suitable metals, M, in someembodiments. In some embodiments, the substrate 10 includes silicondioxide, silicon nitride, aluminum oxide, hafnium oxide, lanthanumoxide, and combinations thereof.

The photoresist layer 15 is a photosensitive layer that is patterned byexposure to actinic radiation. Typically, the chemical properties of thephotoresist regions struck by incident radiation change in a manner thatdepends on the type of photoresist used. Photoresist layers 15 aretypically positive resists or negative resists. Conventionally, positiveresist refers to a photoresist material that when exposed to radiation(typically UV light) becomes soluble in a developer, while the region ofthe photoresist that is non-exposed (or exposed less) is insoluble inthe developer. Negative resist, on the other hand, conventionally refersto a photoresist material that when exposed to radiation becomesinsoluble in the developer, while the region of the photoresist that isnon-exposed (or exposed less) is soluble in the developer. The region ofa negative resist that becomes insoluble upon exposure to radiation maybecome insoluble due to a cross-linking reaction caused by the exposureto radiation.

Whether a resist is a positive or negative may depend on the type ofdeveloper used to develop the resist. For example, some positivephotoresists provide a positive pattern, (i.e.—the exposed regions areremoved by the developer), when the developer is an aqueous-baseddeveloper, such as a tetramethylammonium hydroxide (TMAH) solution. Onthe other hand, the same photoresist provides a negative pattern(i.e.—the unexposed regions are removed by the developer) when thedeveloper is an organic solvent. Further, in some negative photoresistsdeveloped with the TMAH solution, the unexposed regions of thephotoresist are removed by the TMAH, and the exposed regions of thephotoresist, that undergo cross-linking upon exposure to actinicradiation, remain on the substrate after development.

Photoresists according to the present disclosure include a polymer resinalong with one or more photoactive compounds (PACs) in a solvent, insome embodiments. In some embodiments, the polymer resin includes ahydrocarbon structure (such as an alicyclic hydrocarbon structure) thatcontains one or more groups that will decompose (e.g., acid labilegroups or acid leaving groups) or otherwise react when mixed with acids,bases, or free radicals generated by the PACs (as further describedbelow). In some embodiments, the hydrocarbon structure includes arepeating unit that forms a skeletal backbone of the polymer resin. Thisrepeating unit may include acrylic esters, methacrylic esters, crotonicesters, vinyl esters, maleic diesters, fumaric diesters, itaconicdiesters, (meth)acrylonitrile, (meth)acrylamides, styrenes, vinylethers, combinations of these, or the like.

In some embodiments, the photoresist includes a polymer resin havingacid leaving groups selected from the following:

Specific structures that are utilized for the repeating unit of thehydrocarbon structure in some embodiments, include one or more of methylacrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butylacrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate,2-ethylhexyl acrylate, acetoxyethyl acrylate, phenyl acrylate,2-hydroxyethyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethylacrylate, 2-(2-methoxyethoxy)ethyl acrylate, cyclohexyl acrylate, benzylacrylate, 2-alkyl-2-adamantyl (meth)acrylate ordialkyl(1-adamantyl)methyl (meth)acrylate, methyl methacrylate, ethylmethacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butylmethacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexylmethacrylate, 2-ethylhexyl methacrylate, acetoxyethyl methacrylate,phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethylmethacrylate, 2-ethoxyethyl methacrylate, 2-(2-methoxyethoxy)ethylmethacrylate, cyclohexyl methacrylate, benzyl methacrylate,3-chloro-2-hydroxypropyl methacrylate, 3-acetoxy-2-hydroxypropylmethacrylate, 3-chloroacetoxy-2-hydroxypropyl methacrylate, butylcrotonate, hexyl crotonate, or the like. Examples of the vinyl estersinclude vinyl acetate, vinyl propionate, vinyl butylate, vinylmethoxyacetate, vinyl benzoate, dimethyl maleate, diethyl maleate,dibutyl maleate, dimethyl fumarate, diethyl fumarate, dibutyl fumarate,dimethyl itaconate, diethyl itaconate, dibutyl itaconate, acrylamide,methyl acrylamide, ethyl acrylamide, propyl acrylamide, n-butylacrylamide, tert-butyl acrylamide, cyclohexyl acrylamide, 2-methoxyethylacrylamide, dimethyl acrylamide, diethyl acrylamide, phenyl acrylamide,benzyl acrylamide, methacrylamide, methyl methacrylamide, ethylmethacrylamide, propyl methacrylamide, n-butyl methacrylamide,tert-butyl methacrylamide, cyclohexyl methacrylamide, 2-methoxyethylmethacrylamide, dimethyl methacrylamide, diethyl methacrylamide, phenylmethacrylamide, benzyl methacrylamide, methyl vinyl ether, butyl vinylether, hexyl vinyl ether, methoxyethyl vinyl ether, dimethylaminoethylvinyl ether, or the like. Examples of styrenes include styrene, methylstyrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropylstyrene, butyl styrene, methoxy styrene, butoxy styrene, acetoxystyrene, chloro styrene, dichloro styrene, bromo styrene, vinyl methylbenzoate, α-methyl styrene, maleimide, vinylpyridine, vinylpyrrolidone,vinylcarbazole, combinations of these, or the like.

In some embodiments, the repeating unit of the hydrocarbon structurealso has either a monocyclic or a polycyclic hydrocarbon structuresubstituted into it, or the monocyclic or polycyclic hydrocarbonstructure is the repeating unit, in order to form an alicyclichydrocarbon structure. Specific examples of monocyclic structures insome embodiments include bicycloalkane, tricycloalkane,tetracycloalkane, cyclopentane, cyclohexane, or the like. Specificexamples of polycyclic structures in some embodiments includeadamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane,or the like.

The group which will decompose, otherwise known as a leaving group, isattached to the hydrocarbon structure so that, it will react with theacids/bases/free radicals generated by the PACs during exposure. Leavinggroups that react with acids are known as acid leaving groups. In someembodiments, the group which will decompose is a carboxylic acid group,a fluorinated alcohol group, a phenolic alcohol group, a sulfonic group,a sulfonamide group, a sulfonylimido group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (alkylsulfonyl)(alkyl-carbonyl)imidogroup, a bis(alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imidogroup, a bis(alkylsylfonyl)methylene group, a bis(alkylsulfonyl)imidogroup, a tris(alkylcarbonyl methylene group, atris(alkylsulfonyl)methylene group, combinations of these, or the like.Specific groups that are used for the fluorinated alcohol group includefluorinated hydroxyalkyl groups, such as a hexafluoroisopropanol groupin some embodiments. Specific groups that are used for the carboxylicacid group include acrylic acid groups, methacrylic acid groups, or thelike.

In some embodiment, the acid leaving group (ALG) decomposes by theaction of the acid generated by the photoacid generator leaving acarboxylic acid group pendant to the polymer resin chain, as shown inthe ALG de-protect reaction:

In some embodiments, the polymer resin also includes other groupsattached to the hydrocarbon structure that help to improve a variety ofproperties of the polymerizable resin. For example, inclusion of alactone group to the hydrocarbon structure assists to reduce the amountof line edge roughness after the photoresist has been developed, therebyhelping to reduce the number of defects that occur during development.In some embodiments, the lactone groups include rings having five toseven members, although any suitable lactone structure may alternativelybe used for the lactone group.

In some embodiments, the polymer resin includes groups that can assistin increasing the adhesiveness of the photoresist layer 15 to underlyingstructures (e.g., substrate 10). Polar groups may be used to helpincrease the adhesiveness. Suitable polar groups include hydroxylgroups, cyano groups, or the like, although any suitable polar groupmay, alternatively, be used.

Optionally, the polymer resin includes one or more alicyclic hydrocarbonstructures that do not also contain a group, which will decompose insome embodiments. In some embodiments, the hydrocarbon structure thatdoes not contain a group which will decompose includes structures suchas 1-adamantyl(meth)acrylate, tricyclodecanyl (meth)acrylate, cyclohexyl(methacrylate), combinations of these, or the like.

Additionally, some embodiments of the photoresist include one or morephotoactive compounds (PACs). The PACs are photoactive components, suchas photoacid generators, photo base generators, free-radical generators,or the like. The PACs may be positive-acting or negative-acting. In someembodiments in which the PACs are a photoacid generator, the PACsinclude halogenated triazines, onium salts, diazonium salts, aromaticdiazonium salts, phosphonium salts, sulfonium salts, iodonium salts,imide sulfonate, oxime sulfonate, diazodisulfone, disulfone,o-nitrobenzylsulfonate, sulfonated esters, halogenated sulfonyloxydicarboximides, diazodisulfones, α-cyanooxyamine-sulfonates,imidesulfonates, ketodiazosulfones, sulfonyldiazoesters,1,2-di(arylsulfonyl)hydrazines, nitrobenzyl esters, and the s-triazinederivatives, combinations of these, or the like.

Specific examples of photoacid generators includeα-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarb-o-ximide(MDT), N-hydroxy-naphthalimide (DDSN), benzoin tosylate,t-butylphenyl-α-(p-toluenesulfonyloxy)-acetate andt-butyl-α-(p-toluenesulfonyloxy)-acetate, triarylsulfonium anddiaryliodonium hexafluoroantimonates, hexafluoroarsenates,trifluoromethanesulfonates, iodonium perfluorooctanesulfonate,N-camphorsulfonyloxynaphthalimide,N-pentafluorophenylsulfonyloxynaphthalimide, ionic iodonium sulfonatessuch as diaryl iodonium (alkyl or aryl)sulfonate andbis-(di-t-butylphenyl)iodonium camphanylsulfonate,perfluoroalkanesulfonates such as perfluoropentanesulfonate,perfluorooctanesulfonate, perfluoromethanesulfonate, aryl (e.g., phenylor benzyl)triflates such as triphenylsulfonium triflate orbis-(t-butylphenyl)iodonium triflate; pyrogallol derivatives (e.g.,trimesylate of pyrogallol), trifluoromethanesulfonate esters ofhydroxyimides, α,α′-bis-sulfonyl-diazomethanes, sulfonate esters ofnitro-substituted benzyl alcohols, naphthoquinone-4-diazides, alkyldisulfones, or the like.

Structures of photoacid generators according to the embodiments of thedisclosure include:

In some embodiments in which the PACs are free-radical generators, thePACs include n-phenylglycine; aromatic ketones, including benzophenone,N,N′-tetramethyl-4,4′-diaminobenzophenone,N,N′-tetraethyl-4,4′-diaminobenzophenone,4-methoxy-4′-dimethylaminobenzo-phenone,3,3′-dimethyl-4-methoxybenzophenone,p,p′-bis(dimethylamino)benzo-phenone,p,p′-bis(diethylamino)-benzophenone; anthraquinone,2-ethylanthraquinone; naphthaquinone; and phenanthraquinone; benzoinsincluding benzoin, benzoinmethylether, benzoinisopropylether,benzoin-n-butylether, benzoin-phenylether, methylbenzoin andethylbenzoin; benzyl derivatives, including dibenzyl,benzyldiphenyldisulfide, and benzyldimethylketal; acridine derivatives,including 9-phenylacridine, and 1,7-bis(9-acridinyl)heptane;thioxanthones, including 2-chlorothioxanthone, 2-methylthioxanthone,2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, and2-isopropylthioxanthone; acetophenones, including1,1-dichloroacetophenone, p-t-butyldichloro-acetophenone,2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and2,2-dichloro-4-phenoxyacetophenone; 2,4,5-triarylimidazole dimers,including 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer,2-(o-chlorophenyl)-4,5-di-(m-methoxyphenyl imidazole dimer,2-(o-fluorophenyl)-4,5-diphenylimidazole dimer,2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer,2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer,2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer,2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer and2-(p-methylmercaptophenyl)-4,5-diphenylimidazole dimmer; combinations ofthese, or the like.

In some embodiments in which the PACs are photobase generators, the PACsincludes quaternary ammonium dithiocarbamates, a aminoketones,oxime-urethane containing molecules such as dibenzophenoneoximehexamethylene diurethan, ammonium tetraorganylborate salts, andN-(2-nitrobenzyloxycarbonyl)cyclic amines, combinations of these, or thelike.

As one of ordinary skill in the art will recognize, the chemicalcompounds listed herein are merely intended as illustrated examples ofthe PACs and are not intended to limit the embodiments to only thosePACs specifically described. Rather, any suitable PAC may be used, andall such PACs are fully intended to be included within the scope of thepresent embodiments.

In some embodiments, a cross-linking agent is added to the photoresist.The cross-linking agent reacts with one group from one of thehydrocarbon structures in the polymer resin and also reacts with asecond group from a separate one of the hydrocarbon structures in orderto cross-link and bond the two hydrocarbon structures together. Thisbonding and cross-linking increases the molecular weight of the polymerproducts of the cross-linking reaction and increases the overall linkingdensity of the photoresist. Such an increase in density and linkingdensity helps to improve the resist pattern.

In some embodiments the cross-linking agent has the following structure:

wherein C is carbon, n ranges from 1 to 15; A and B independentlyinclude a hydrogen atom, a hydroxyl group, a halide, an aromatic carbonring, or a straight or cyclic alkyl, alkoxyl/fluoro, alkyl/fluoroalkoxylchain having a carbon number of between 1 and 12, and each carbon Ccontains A and B; a first terminal carbon C at a first end of a carbon Cchain includes X and a second terminal carbon C at a second end of thecarbon chain includes Y, wherein X and Y independently include an aminegroup, a thiol group, a hydroxyl group, an isopropyl alcohol group, oran isopropyl amine group, except when n=1 then X and Y are bonded to thesame carbon C. Specific examples of materials that may be used as thecross-linking agent include the following:

Alternatively, instead of or in addition to the cross-linking agentbeing added to the photoresist composition, a coupling reagent is addedin some embodiments, in which the coupling reagent is added in additionto the cross-linking agent. The coupling reagent assists thecross-linking reaction by reacting with the groups on the hydrocarbonstructure in the polymer resin before the cross-linking reagent,allowing for a reduction in the reaction energy of the cross-linkingreaction and an increase in the rate of reaction. The bonded couplingreagent then reacts with the cross-linking agent, thereby coupling thecross-linking agent to the polymer resin.

Alternatively, in some embodiments in which the coupling reagent isadded to the photoresist without the cross-linking agent, the couplingreagent is used to couple one group from one of the hydrocarbonstructures in the polymer resin to a second group from a separate one ofthe hydrocarbon structures in order to cross-link and bond the twopolymers together. However, in such an embodiment the coupling reagent,unlike the cross-linking agent, does not remain as part of the polymer,and only assists in bonding one hydrocarbon structure directly toanother hydrocarbon structure.

In some embodiments, the coupling reagent has the following structure:

where R is a carbon atom, a nitrogen atom, a sulfur atom, or an oxygenatom; M includes a chlorine atom, a bromine atom, an iodine atom, —NO₂;—SO₃—; —H—; —CN; —NCO, —OCN; —CO₂—; —OH; —OR*, —OC(O)CR*; —SR,—SO2N(R*)₂; —SO₂R*; SOR; —OC(O)R*; —C(O)OR*; —C(O)R*; —Si(OR*)₃;—Si(R*)₃; epoxy groups, or the like; and R* is a substituted orunsubstituted C1-C12 alkyl, C1-C12 aryl, C1-C12 aralkyl, or the like.Specific examples of materials used as the coupling reagent in someembodiments include the following:

In some embodiments, the photoresist includes a protective polymer thatforms a protective layer 20 when applied to a layer to be patterned orsubstrate 10. In some embodiments, the protective polymer has pendantfluorocarbon groups and pendant acid leaving groups. In an embodiment, amain chain of the polymer having pendant fluorocarbon groups and pendantacid leaving groups is a polyhydroxystyrene, a polyacrylate, or apolymer formed from a 1 to 10 carbon monomer. In an embodiment, thepolymer having pendant fluorocarbon groups and pendant acid leavinggroups includes from about 0.1 wt. % to about 10 wt. % of one or morepolar functional groups selected from the group consisting —OH, —NH₃,—NH₂, and —SO₃ based on the total weight of the polymer havingfluorocarbon groups.

In an embodiment, the polymer having pendant fluorocarbon groups andpendant acid leaving groups includes from about 30 wt. % to about 70 wt.% of the pendant fluorocarbon groups and from about 30 wt. % to about 70wt. % of the pendant acid leaving groups based on the total weight ofthe polymer having pendant fluorocarbon groups and pendant acid leavinggroups.

In an embodiment, the pendant fluorocarbon groups are attached to apolymer main chain via a linking unit R1 of at least one selected fromthe group consisting of 1-9 carbon unbranched, branched, cyclic,noncylic, saturated, or unsaturated hydrocarbon with optional halogensubstituents; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—; —C(═O)N—;—SO₂O—; —SO₂S—; —SO—; —SO₂—; and —C(═O)—. In an embodiment, thefluorocarbon pendant group is selected from the group consisting ofC_(x)F_(y), where 1≤x≤9 and 3≤y≤12; and —(C(CF₃)₂OH)—. Examples ofC_(x)F_(y) units attached to the polymer chain via a linking unit R1according to embodiments of the disclosure are shown in FIG. 9. Asshown, in some embodiments, C_(x)F_(y) is one or more selected from thegroup consisting of —C₂F₅, —CH₂CH₂C₃F₇, —(C(CF₃)₂OH), —C(═O)OC₄F₉,—CH₂OC₄F₉, and —C(═O)O(C(CF₃)₂OH).

In an embodiment, the pendant acid leaving groups are attached to apolymer main chain via a linking unit R2 of at least one selected fromthe group consisting of 1-9 carbon unbranched, branched, cyclic,noncylic, saturated, or unsaturated hydrocarbon with optional halogensubstituents; phenyl; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—;—C(═O)N—; —SO₂O—; —SO₂S—; —SO—; —SO₂—; —C(═O)—; and —C—O—O—. Examples ofacid leaving groups attached to the polymer chain via a linking unit R2according to embodiments of the disclosure are shown in FIG. 10.

In some embodiments, the amount of protective polymer having pendantfluorocarbon groups and pendant acid leaving groups in thephotoresist/protective polymer mixture ranges from about 1 wt. % toabout 10 wt. % based on the total weight of the photoresist/protectivepolymer mixture. In some embodiments, the protective polymer havingpendant fluorocarbon groups and pendant acid leaving groups has a weightaverage molecular weight of about 3000 to about 15,000. In someembodiments, the protective polymer having pendant fluorocarbon and acidleaving groups has a weight average molecular weight of about 6000 toabout 11,000.

The individual components of the photoresist and the protective polymerare placed into a solvent in order to aid in the mixing and dispensingof the photoresist. To aid in the mixing and dispensing of thephotoresist, the solvent is chosen at least in part based upon thematerials chosen for the polymer resins as well as the PACs. In someembodiments, the solvent is chosen such that the polymer resins(photoresist polymer and protective polymer) and the PACs can be evenlydissolved into the solvent and dispensed upon the layer to be patterned.

In some embodiments, the solvent is an organic solvent, and includes oneor more of any suitable solvent such as ketones, alcohols, polyalcohols,ethers, glycol ethers, cyclic ethers, aromatic hydrocarbons, esters,propionates, lactates, lactic esters, alkylene glycol monoalkyl ethers,alkyl lactates, alkyl alkoxypropionates, cyclic lactones, monoketonecompounds that contain a ring, alkylene carbonates, alkyl alkoxyacetate,alkyl pyruvates, lactate esters, ethylene glycol alkyl ether acetates,diethylene glycols, propylene glycol alkyl ether acetates, alkyleneglycol alkyl ether esters, alkylene glycol monoalkyl esters, or thelike.

Specific examples of materials that may be used as the solvent for thephotoresist include, acetone, methanol, ethanol, toluene, xylene,4-hydroxy-4-methyl-2-pentatone, tetrahydrofuran, methyl ethyl ketone,cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycol,ethylene glycol monoacetate, ethylene glycol dimethyl ether, ethyleneglycol dimethyl ether, ethylene glycol methylethyl ether, ethyleneglycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolveacetate, diethylene glycol, diethylene glycol monoacetate, diethyleneglycol monomethyl ether, diethylene glycol diethyl ether, diethyleneglycol dimethyl ether, diethylene glycol ethylmethyl ether,diethethylene glycol monoethyl ether, diethylene glycol monobutyl ether,ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate,methyl 2-hydroxy-2-methylbutanate, methyl 3-methoxypropionate, ethyl3-methoxypropionate, methyl 3-ethoxypropionate, ethyl3-ethoxypropionate, methyl acetate, ethyl acetate, propyl acetate, butylacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate,propylene glycol, propylene glycol monoacetate, propylene glycolmonoethyl ether acetate, propylene glycol monomethyl ether acetate,propylene glycol monopropyl methyl ether acetate, propylene glycolmonobutyl ether acetate, propylene glycol monobutyl ether acetate,propylene glycol monomethyl ether propionate, propylene glycol monoethylether propionate, propylene glycol methyl ether acetate, propyleneglycol ethyl ether acetate, ethylene glycol monomethyl ether acetate,ethylene glycol monoethyl ether acetate, propylene glycol monomethylether, propylene glycol monoethyl ether, propylene glycol monopropylether, propylene glycol monobutyl ether, ethylene glycol monomethylether, ethylene glycol monoethyl ether, ethyl 3-ethoxypropionate, methyl3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl3-methoxypropionate, β-propiolactone, β-butyrolactone, γ-butyrolactone,α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone,γ-caprolactone, γ-octanoic lactone, α-hydroxy-γ-butyrolactone,2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone,4-methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone,2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone,3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone,2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone,2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone,3-decanone, 4-decanone, 5-hexene-2-one, 3-pentene-2-one, cyclopentanone,2-methylcyclopentanone, 3-methylcyclopentanone,2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone,cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone,4-ethylcyclohexanone, 2,2-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone,2-methylcycloheptanone, 3-methylcycloheptanone, propylene carbonate,vinylene carbonate, ethylene carbonate, butylene carbonate,acetate-2-methoxyethyl, acetate-2-ethoxyethyl,acetate-2-(2-ethoxyethoxy)ethyl, acetate-3-methoxy-3-methylbutyl,acetate-1-methoxy-2-propyl, dipropylene glycol, monomethylether,monoethylether, monopropylether, monobutylether, monophenylether,dipropylene glycol monoacetate, dioxane, methyl pyruvate, ethylpyruvate, propyl pyruvate, methyl methoxypropionate, ethylethoxypropionate, n-methylpyrrolidone (NMP), 2-methoxyethyl ether(diglyme), ethylene glycol monomethyl ether, propylene glycol monomethylether, methyl propionate, ethyl propionate, ethyl ethoxy propionate,methylethyl ketone, cyclohexanone, 2-heptanone, cyclopentanone,cyclohexanone, ethyl 3-ethoxypropionate, propylene glycol methyl etheracetate (PGMEA), methylene cellosolve, 2-ethoxyethanol,N-methylformamide, N,N-dimethylformamide, N-methylformanilide,N-methylacetamide, N,N-dimethylacetamide, dimethylsulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone, isophorone, caproic acid,caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate,ethyl benzoate, diethyl oxalate, diethyl maleate, phenyl cellosolveacetate, or the like.

As one of ordinary skill in the art will recognize, the materials listedand described above as examples of materials that may be used for thesolvent component of the photoresist are merely illustrative and are notintended to limit the embodiments. Rather, any suitable materials thatdissolve the polymer resin and the PACs may be used to help mix andapply the photoresist. All such materials are fully intended to beincluded within the scope of the embodiments.

Additionally, while individual ones of the above-described materials maybe used as the solvent for the photoresist and protective polymer, inother embodiments more than one of the above described materials areused. For example, in some embodiments, the solvent includes acombination mixture of two or more of the materials described. All suchcombinations are fully intended to be included within the scope of theembodiments.

In addition to the polymer resins, the PACs, the solvents, thecross-linking agent, and the coupling reagent, some embodiments of thephotoresist also includes a number of other additives that assist thephotoresist to obtain high resolution. For example, some embodiments ofthe photoresist also includes surfactants in order to help improve theability of the photoresist to coat the surface on which it is applied.In some embodiments, the surfactants include nonionic surfactants,polymers having fluorinated aliphatic groups, surfactants that containat least one fluorine atom and/or at least one silicon atom,polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers,polyoxyethylene-polyoxypropylene block copolymers, sorbitan fatty acidesters, and polyoxyethylene sorbitan fatty acid esters.

Specific examples of materials used as surfactants in some embodimentsinclude polyoxyethylene lauryl ether, polyoxyethylene stearyl ether,polyoxyethylene cetyl ether, polyoxyethylene oleyl ether,polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether,sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate,sorbitan monooleate, sorbitan trioleate, sorbitan tristearate,polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitanmonopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylenesorbitan trioleate, polyoxyethylene sorbitan tristearate, polyethyleneglycol distearate, polyethylene glycol dilaurate, polyethylene glycoldilaurate, polyethylene glycol, polypropylene glycol,polyoxyethylenestearyl ether, polyoxyethylene cetyl ether, fluorinecontaining cationic surfactants, fluorine containing nonionicsurfactants, fluorine containing anionic surfactants, cationicsurfactants and anionic surfactants, polyethylene glycol, polypropyleneglycol, polyoxyethylene cetyl ether, combinations thereof, or the like.

Another additive added to some embodiments of the photoresistcomposition and protective layer composition is a quencher, whichinhibits diffusion of the generated acids/bases/free radicals within thephotoresist. The quencher improves the resist pattern configuration aswell as the stability of the photoresist over time. In an embodiment,the quencher is an amine, such as a second lower aliphatic amine, atertiary lower aliphatic amine, or the like. Specific examples of aminesinclude trimethylamine, diethylamine, triethylamine, di-n-propylamine,tri-n-propylamine, tripentylamine, diethanolamine, and triethanolamine,alkanolamine, combinations thereof, or the like.

Some embodiments of quenchers include:

In some embodiments, the quencher is a photo decomposed base. Examplesof photo decomposed bases are shown below, where R′ is an alicyclicgroup of 5 or more carbon atoms which may have a substituent, X is adivalent linking group, Y is a linear, branched or cyclic alkylene groupor an arylene group; Rf is a hydrocarbon group containing a fluorineatom, and M is an organic cation or a metal cation:

Example

In some embodiments, an organic acid is used as the quencher. Specificembodiments of organic acids include malonic acid, citric acid, malicacid, succinic acid, benzoic acid, salicylic acid; phosphorous oxo acidand its derivatives, such as phosphoric acid and derivatives thereofsuch as its esters, phosphoric acid di-n-butyl ester and phosphoric aciddiphenyl ester; phosphonic acid and derivatives thereof such as itsester, such as phosphonic acid dimethyl ester, phosphonic aciddi-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester,and phosphonic acid dibenzyl ester; and phosphinic acid and derivativesthereof such as its esters, including phenylphosphinic acid.

Another additive added to some embodiments of the photoresist is astabilizer, which assists in preventing undesired diffusion of the acidsgenerated during exposure of the photoresist. In some embodiments, thestabilizer includes nitrogenous compounds, including aliphatic primary,secondary, and tertiary amines; cyclic amines, including piperidines,pyrrolidines, morpholines; aromatic heterocycles, including pyridines,pyrimidines, purines; imines, including diazabicycloundecene,guanidines, imides, amides, or the like. Alternatively, ammonium saltsare also be used for the stabilizer in some embodiments, includingammonium, primary, secondary, tertiary, and quaternary alkyl- andaryl-ammonium salts of alkoxides, including hydroxide, phenolates,carboxylates, aryl and alkyl sulfonates, sulfonamides, or the like.Other cationic nitrogenous compounds, including pyridinium salts andsalts of other heterocyclic nitrogenous compounds with anions, such asalkoxides, including hydroxide, phenolates, carboxylates, aryl and alkylsulfonates, sulfonamides, or the like, are used in some embodiments.

Another additive in some embodiments of the photoresist is a dissolutioninhibitor to help control dissolution of the photoresist duringdevelopment. In an embodiment bile-salt esters may be utilized as thedissolution inhibitor. Specific examples of dissolution inhibitors insome embodiments include cholic acid, deoxycholic acid, lithocholicacid, t-butyl deoxycholate, t-butyl lithocholate, and t-butyl-3-acetyllithocholate.

Another additive in some embodiments of the photoresist is aplasticizer. Plasticizers may be used to reduce delamination andcracking between the photoresist and underlying layers (e.g., the layerto be patterned). Plasticizers include monomeric, oligomeric, andpolymeric plasticizers, such as oligo- and polyethyleneglycol ethers,cycloaliphatic esters, and non-acid reactive steroidaly-derivedmaterials. Specific examples of materials used for the plasticizer insome embodiments include dioctyl phthalate, didodecyl phthalate,triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresylphosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerine, orthe like.

A coloring agent is another additive included in some embodiments of thephotoresist. The coloring agent observers examine the photoresist andfind any defects that may need to be remedied prior to furtherprocessing. In some embodiments, the coloring agent is a triarylmethanedye or a fine particle organic pigment. Specific examples of materialsin some embodiments include crystal violet, methyl violet, ethyl violet,oil blue #603, Victoria Pure Blue BOH, malachite green, diamond green,phthalocyanine pigments, azo pigments, carbon black, titanium oxide,brilliant green dye (C. I. 42020), Victoria Pure Blue FGA (Linebrow),Victoria BO (Linebrow) (C. I. 42595), Victoria Blue BO (C. I. 44045),rhodamine 6G (C. I. 45160), benzophenone compounds, such as2,4-dihydroxybenzophenone and 2,2′,4,4′-tetrahydroxybenzophenone;salicylic acid compounds, such as phenyl salicylate and 4-t-butylphenylsalicylate; phenylacrylate compounds, such asethyl-2-cyano-3,3-diphenylacrylate, and2′-ethylhexyl-2-cyano-3,3-diphenylacrylate; benzotriazole compounds,such as 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, and2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole;coumarin compounds, such as 4-methyl-7-diethylamino-1-benzopyran-2-one;thioxanthone compounds, such as diethylthioxanthone; stilbene compounds,naphthalic acid compounds, azo dyes, phthalocyanine blue, phthalocyaninegreen, iodine green, Victoria blue, crystal violet, titanium oxide,naphthalene black, Photopia methyl violet, bromphenol blue andbromcresol green; laser dyes, such as Rhodamine G6, Coumarin 500, DCM(4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H pyran)),Kiton Red 620, Pyrromethene 580, or the like. Additionally, one or morecoloring agents may be used in combination to provide the desiredcoloring.

Adhesion additives are added to some embodiments of the photoresist topromote adhesion between the photoresist and an underlying layer uponwhich the photoresist has been applied (e.g., the layer to bepatterned). In some embodiments, the adhesion additives include a silanecompound with at least one reactive substituent such as a carboxylgroup, a methacryloyl group, an isocyanate group and/or an epoxy group.Specific examples of the adhesion components include trimethoxysilylbenzoic acid, γ-methacryloxypropyl trimethoxy silane,vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatepropyltriethoxy silane, γ-glycidoxypropyl trimethoxy silane,β-(3,4-epoxycyclohexyl)ethyl trimethoxy silane, benzimidazoles andpolybenzimidazoles, a lower hydroxyalkyl substituted pyridinederivative, a nitrogen heterocyclic compound, urea, thiourea, anorganophosphorus compound, 8-oxyquinoline, 4-hydroxypteridine andderivatives, 1,10-phenanthroline and derivatives, 2,2′-bipyridine andderivatives, benzotriazoles, organophosphorus compounds,phenylenediamine compounds, 2-amino-1-phenylethanol,N-phenylethanolamine, N-ethyldiethanolamine, N-ethylethanolamine andderivatives, benzothiazole, and a benzothiazoleamine salt having acyclohexyl ring and a morpholine ring,3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane,3-methacryloyloxypropyltrimethoxysilane, vinyl trimethoxysilane,combinations thereof, or the like.

Surface leveling agents are added to some embodiments of the photoresistto assist a top surface of the photoresist to be level, so thatimpinging light will not be adversely modified by an unlevel surface. Insome embodiments, surface leveling agents include fluoroaliphaticesters, hydroxyl terminated fluorinated polyethers, fluorinated ethyleneglycol polymers, silicones, acrylic polymer leveling agents,combinations thereof, or the like.

Some embodiments of the photoresist include metal oxide nanoparticles.In some embodiments, the photoresist includes one or more metal oxidesnanoparticles selected from the group consisting of titanium dioxide,zinc oxide, zirconium dioxide, nickel oxide, cobalt oxide, manganeseoxide, copper oxides, iron oxides, strontium titanate, tungsten oxides,vanadium oxides, chromium oxides, tin oxides, hafnium oxide, indiumoxide, cadmium oxide, molybdenum oxide, tantalum oxides, niobium oxide,aluminum oxide, and combinations thereof. As used herein, nanoparticlesare particles having an average particle size between 1 and 10 nm. Insome embodiments, the metal oxide nanoparticles have an average particlesize between 2 and 5 nm. In some embodiments, the amount of metal oxidenanoparticles in the photoresist composition ranges from about 0.1 wt. %to about 20 wt. % based on the total weight of the photoresistcomposition. In some embodiments, the amount of nanoparticles in thephotoresist composition ranges from about 1 wt. % to about 10 wt. %based on the total weight of the photoresist composition.

In some embodiments, the metal oxide nanoparticles are complexed with aligand. In some embodiments, the ligand is a carboxylic acid or sulfonicacid ligand. For example, in some embodiments, zirconium oxide orhafnium oxide nanoparticles are complexed with methacrylic acid forminghafnium methacrylic acid (HfMAA) or zirconium oxide (ZrMAA). In someembodiments, the metal oxide nanoparticles are complexed with ligandsincluding aliphatic or aromatic groups. The aliphatic or aromatic groupsmay be unbranched or branched with cyclic or noncyclic saturated pendantgroups containing 1-9 carbons, including alkyl groups, alkenyl groups,and phenyl groups. The branched groups may be further substituted withoxygen or halogen.

In some embodiments, the photoresist composition includes about 0.1 wt.% to about 20 wt. % of the ligand. In some embodiments, the photoresistincludes about 1 wt. % to about 10 wt. % of the ligand. In someembodiments, the ligand is HfMAA or ZrMAA dissolved at about a 5 wt. %to about 10 wt. % weight range in a coating solvent, such as propyleneglycol methyl ether acetate (PGMEA).

In some embodiments, the polymer resins (photoresist resin andprotective resin) and the PACs, along with any desired additives orother agents, are added to the solvent for application. Once added, themixture is then mixed in order to achieve a homogenous compositionthroughout the photoresist to ensure that there are no defects caused byuneven mixing or nonhomogenous composition of the photoresist. Oncemixed together, the photoresist may either be stored prior to its usageor used immediately.

In some embodiments, a protective polymer composition is preparedseparate from the photoresist composition, and applied separately to thephotoresist coated substrate, as shown in FIGS. 3A-3D.

The protective polymer composition includes any polymer selected fromthe protective polymers previously disclosed herein having pendantfluorocarbon groups and pendant acid leaving groups. The protectivepolymer composition further includes any of the photoacid generatorsdescribed herein. In some embodiments, the protective polymercomposition includes a quencher, such as any of the quenchers describedherein. The quencher can include a photo decomposable base as describedherein. In some embodiments, the amount of photoacid generator,quencher, and/or photo decomposable base ranges from about 3 wt. % toabout 30 wt. % of polymer resin in the protective layer 20.

In an embodiment, a main chain of the polymer having fluorocarbonpendant groups is a polyhydroxystyrene, a polyacrylate, or a polymerformed from a 1 to 10 carbon monomer. In an embodiment, the polymerhaving pendant fluorocarbon groups and pendant acid leaving groupsincludes from about 0.1 wt. % to about 10 wt. % of one or more polarfunctional groups selected from the group consisting —OH, —NH₃, —NH₂,and —SO₃ based on the total weight of the polymer having fluorocarbongroups. In an embodiment, the polymer having pendant fluorocarbon groupsand pendant acid leaving groups includes from about 30 wt. % to about 70wt. % of the pendant fluorocarbon groups and from about 30 wt. % toabout 70 wt. % of the acid leaving group based on the total weight ofthe polymer pendant fluorocarbon groups and pendant acid leaving groups.

In an embodiment, the pendant fluorocarbon groups are attached to apolymer main chain via a linking unit R1 of at least one selected fromthe group consisting of 1-9 carbon unbranched, branched, cyclic,noncylic, saturated, or unsaturated hydrocarbon with optional halogensubstituents; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—; —C(═O)N—;—SO₂O—; —SO₂S—; —SO—; —SO₂—; and —C(═O)—. In an embodiment, the pendantfluorocarbon group is selected from the group consisting of C_(x)F_(y),where 1≤x≤9 and 3≤y≤12; and —(C(CF₃)₂OH)—. Examples of C_(x)F_(y) unitsattached to the polymer chain via a linking unit R1 according toembodiments of the disclosure are shown in FIG. 9. As shown, in someembodiments, C_(x)F_(y) is one or more selected from the groupconsisting of —C₂F₅, —CH₂CH₂C₃F₇, —(C(CF₃)₂OH), —C(═O)OC₄F₉, —CH₂OC₄F₉,and —C(═O)O(C(CF₃)₂OH).

In an embodiment, the pendant acid leaving groups are attached to apolymer main chain via a linking unit R2 of at least one selected fromthe group consisting of 1-9 carbon unbranched, branched, cyclic,noncylic, saturated, or unsaturated hydrocarbon with optional halogensubstituents; phenyl; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—;—C(═O)N—; —SO₂O—; —SO₂S—; —SO—; —SO₂—; —C(═O)—; and —C—O—O—. Examples ofacid leaving groups attached to the polymer chain via a linking unit R2according to embodiments of the disclosure are shown in FIG. 10,including:

In some embodiments, the amount of protective polymer having pendantfluorocarbon groups and pendant acid leaving groups in thephotoresist/protective polymer mixture ranges from about 1 wt. % toabout 10 wt. % based on the total weight of the photoresist/protectivepolymer mixture. In some embodiments, the protective polymer havingpendant fluorocarbon groups and pendant acid leaving groups has a weightaverage molecular weight of about 3000 to about 15,000. In someembodiments, the protective polymer having fluorocarbon pendant groupshas a weight average molecular weight of about 6000 to about 11,000.

The protective polymer is placed into a solvent in order to aid indispensing of the protective polymer. To aid in the mixing anddispensing of the protective polymer, the solvent is chosen at least inpart based upon the materials chosen for the polymer resins as well asthe PACs. In some embodiments, the solvent is an organic solvent, andincludes one or more of any suitable solvent such as ketones, alcohols,polyalcohols, ethers, glycol ethers, cyclic ethers, aromatichydrocarbons, esters, propionates, lactates, lactic esters, alkyleneglycol monoalkyl ethers, alkyl lactates, alkyl alkoxypropionates, cycliclactones, monoketone compounds that contain a ring, alkylene carbonates,alkyl alkoxyacetate, alkyl pyruvates, lactate esters, ethylene glycolalkyl ether acetates, diethylene glycols, propylene glycol alkyl etheracetates, alkylene glycol alkyl ether esters, alkylene glycol monoalkylesters, or the like.

Specific examples of materials that may be used as the solvent for theprotective polymer include, acetone, methanol, ethanol, toluene, xylene,4-hydroxy-4-methyl-2-pentatone, tetrahydrofuran, methyl ethyl ketone,cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycol,ethylene glycol monoacetate, ethylene glycol dimethyl ether, ethyleneglycol dimethyl ether, ethylene glycol methylethyl ether, ethyleneglycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolveacetate, diethylene glycol, diethylene glycol monoacetate, diethyleneglycol monomethyl ether, diethylene glycol diethyl ether, diethyleneglycol dimethyl ether, diethylene glycol ethylmethyl ether,diethethylene glycol monoethyl ether, diethylene glycol monobutyl ether,ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate,methyl 2-hydroxy-2-methylbutanate, methyl 3-methoxypropionate, ethyl3-methoxypropionate, methyl 3-ethoxypropionate, ethyl3-ethoxypropionate, methyl acetate, ethyl acetate, propyl acetate, butylacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate,propylene glycol, propylene glycol monoacetate, propylene glycolmonoethyl ether acetate, propylene glycol monomethyl ether acetate,propylene glycol monopropyl methyl ether acetate, propylene glycolmonobutyl ether acetate, propylene glycol monobutyl ether acetate,propylene glycol monomethyl ether propionate, propylene glycol monoethylether propionate, propylene glycol methyl ether acetate, propyleneglycol ethyl ether acetate, ethylene glycol monomethyl ether acetate,ethylene glycol monoethyl ether acetate, propylene glycol monomethylether, propylene glycol monoethyl ether, propylene glycol monopropylether, propylene glycol monobutyl ether, ethylene glycol monomethylether, ethylene glycol monoethyl ether, ethyl 3-ethoxypropionate, methyl3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl3-methoxypropionate, β-propiolactone, β-butyrolactone, γ-butyrolactone,α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone,γ-caprolactone, γ-octanoic lactone, α-hydroxy-γ-butyrolactone,2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone,4-methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone,2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone,3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone,2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone,2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone,3-decanone, 4-decanone, 5-hexene-2-one, 3-pentene-2-one, cyclopentanone,2-methylcyclopentanone, 3-methylcyclopentanone,2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone,cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone,4-ethylcyclohexanone, 2,2-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone,2-methylcycloheptanone, 3-methylcycloheptanone, propylene carbonate,vinylene carbonate, ethylene carbonate, butylene carbonate,acetate-2-methoxyethyl, acetate-2-ethoxyethyl,acetate-2-(2-ethoxyethoxy)ethyl, acetate-3-methoxy-3-methylbutyl,acetate-1-methoxy-2-propyl, dipropylene glycol, monomethylether,monoethylether, monopropylether, monobutylether, monophenylether,dipropylene glycol monoacetate, dioxane, methyl pyruvate, ethylpyruvate, propyl pyruvate, methyl methoxypropionate, ethylethoxypropionate, n-methylpyrrolidone (NMP), 2-methoxyethyl ether(diglyme), ethylene glycol monomethyl ether, propylene glycol monomethylether, methyl propionate, ethyl propionate, ethyl ethoxy propionate,methylethyl ketone, cyclohexanone, 2-heptanone, cyclopentanone,cyclohexanone, ethyl 3-ethoxypropionate, propylene glycol methyl etheracetate (PGMEA), methylene cellosolve, 2-ethoxyethanol,N-methylformamide, N,N-dimethylformamide, N-methylformanilide,N-methylacetamide, N,N-dimethylacetamide, dimethylsulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone, isophorone, caproic acid,caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate,ethyl benzoate, diethyl oxalate, diethyl maleate, phenyl cellosolveacetate, or the like.

Some embodiments of the protective layer composition include one or morephotoactive compounds (PACs). In some embodiments, the PACs arephotoacid generators. The PACs may be positive-acting ornegative-acting. In some embodiments in which the PACs are a photoacidgenerator, the PACs include halogenated triazines, onium salts,diazonium salts, aromatic diazonium salts, phosphonium salts, sulfoniumsalts, iodonium salts, imide sulfonate, oxime sulfonate, diazodisulfone,disulfone, o-nitrobenzylsulfonate, sulfonated esters, halogenatedsulfonyloxy dicarboximides, diazodisulfones, α-cyanooxyamine-sulfonates,imidesulfonates, ketodiazosulfones, sulfonyldiazoesters,1,2-di(arylsulfonyl)hydrazines, nitrobenzyl esters, and the s-triazinederivatives, combinations of these, or the like.

Specific examples of photoacid generators includeα-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarb-o-ximide(MDT), N-hydroxy-naphthalimide (DDSN), benzoin tosylate,t-butylphenyl-α-(p-toluenesulfonyloxy)-acetate andt-butyl-α-(p-toluenesulfonyloxy)-acetate, triarylsulfonium anddiaryliodonium hexafluoroantimonates, hexafluoroarsenates,trifluoromethanesulfonates, iodonium perfluorooctanesulfonate,N-camphorsulfonyloxynaphthalimide,N-pentafluorophenylsulfonyloxynaphthalimide, ionic iodonium sulfonatessuch as diaryl iodonium (alkyl or aryl)sulfonate andbis-(di-t-butylphenyl)iodonium camphanylsulfonate,perfluoroalkanesulfonates such as perfluoropentanesulfonate,perfluorooctanesulfonate, perfluoromethanesulfonate, aryl (e.g., phenylor benzyl)triflates such as triphenylsulfonium triflate orbis-(t-butylphenyl)iodonium triflate; pyrogallol derivatives (e.g.,trimesylate of pyrogallol), trifluoromethanesulfonate esters ofhydroxyimides, α,α′-bis-sulfonyl-diazomethanes, sulfonate esters ofnitro-substituted benzyl alcohols, naphthoquinone-4-diazides, alkyldisulfones, or the like.

Structures of photoacid generators according to the embodiments of thedisclosure include:

In some embodiments, the concentration of the photoacid generator isfrom about 3 wt. % to about 30 wt. % based on the total weight of thephotoacid generator and the polymer having pendant fluorocarbon and acidleaving groups.

In some embodiments, the protective polymer compositions includes fromabout 3 wt. % to about 30 wt. % of a quencher or photo decomposed basebased on the total weight of the polymer having pendant fluorocarbon andacid leaving groups and the quencher or photo decomposed base. Thequencher or photo decomposed base inhibits diffusion of the generatedacids within the protective layer composition. The quencher improves thepattern configuration as well as the stability of the protective layercomposition over time. In an embodiment, the quencher is an amine, suchas a second lower aliphatic amine, a tertiary lower aliphatic amine, orthe like. Specific examples of amines include trimethylamine,diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine,tripentylamine, diethanolamine, and triethanolamine, alkanolamine,combinations thereof, or the like.

Some embodiments of quenchers include:

Examples of photo decomposed bases are shown below, where R¹ is analicyclic group of 5 or more carbon atoms which may have a substituent,X is a divalent linking group, Y is a linear, branched or cyclicalkylene group or an arylene group; Rf is a hydrocarbon group containinga fluorine atom, and M is an organic cation or a metal cation:

Example

As one of ordinary skill in the art will recognize, the materials listedand described above as examples of materials that may be used for thesolvent of the protective polymer are merely illustrative and are notintended to limit the embodiments. Rather, any suitable materials thatdissolve the protective polymer resin to help mix and apply theprotective polymer. All such materials are fully intended to be includedwithin the scope of the embodiments.

Once ready, the photoresist/protective polymer composition is appliedonto the layer to be patterned, as shown in FIG. 2A, such as thesubstrate 10 to form a photoresist layer 15 and protective layer, asshown in FIG. 2B. In some embodiments, the photoresist/protectivepolymer composition is applied using a process such as a spin-on coatingprocess. In other embodiments, a dip coating method, an air-knifecoating method, a curtain coating method, a wire-bar coating method, agravure coating method, a lamination method, an extrusion coatingmethod, combinations of these, or the like are used to coat thephotoresist on the substrate. In some embodiments, the photoresist layer15 thickness ranges from about 10 nm to about 300 nm, and the protectivelayer thickness ranges from about 0.1 nm to about 20 nm. In someembodiments, the thickness of the protective layer ranges from about 1nm to about 15 nm. In some embodiments, the contact angle of theprotective layer to water is greater than 75°.

After the photoresist layer 15 and protective layer 20 have been appliedto the substrate 10, a pre-bake of the photoresist layer is performed insome embodiments to cure and dry the photoresist prior to radiationexposure. The curing and drying of the photoresist layer 15 andprotective layer 20 removes the solvent component while leaving behindthe polymer resins, the PACs, the cross-linking agent, and the otherchosen additives. In some embodiments, the pre-baking is performed at atemperature suitable to evaporate the solvent, such as between about 50°C. and 200° C., although the precise temperature depends upon thematerials chosen for the photoresist. The pre-baking is performed for atime sufficient to cure and dry the photoresist layer and protectivelayer, such as between about 10 seconds to about 10 minutes.

FIG. 11 illustrates a process flow 200 of manufacturing a semiconductordevice according to embodiments of the disclosure. In some embodiments,there are multiple baking operations. In operation S210, a photoresistcomposition is applied to a substrate or a layer to be patterned. Thephotoresist composition may include a protective layer resin, or theprotective layer may be applied to the photoresist in operation S230after baking the photoresist. In some embodiments, where the protectivelayer is separately applied, after applying the protective layer, theprotective layer coating is baked in operation S240. Then the protectivelayer and the photoresist layer are exposed to ultraviolet radiation inpatternwise manner in operation S250. The exposed protective layer andphotoresist layer are then post-exposure baked in operation S260 in someembodiments. Then the protective layer and photoresist layer aredeveloped in operation S270 to form the patterned photoresist layer. Thebaking operations S220, S240, and S260 are performed at a bakingtemperature between 50° C. and 200° C. in some embodiments.

In some embodiments, the photoresist layer 15 and protective layer 20are separately formed, as shown in FIGS. 3A-3D. In some embodiments,each of the photoresist and protective polymer are applied using aprocess such as a spin-on coating process, a dip coating method, anair-knife coating method, a curtain coating method, a wire-bar coatingmethod, a gravure coating method, a lamination method, an extrusioncoating method, combinations of these, or the like. Each of thephotoresist layer 15 and protective layer 20 are pre-baked afterapplication to cure and dry. In some embodiments, each pre-bakingoperation is performed at a temperature suitable to evaporate therespective solvents, such as between about 50° C. and 200° C., for aperiod of time between about 10 seconds to about 10 minutes.

FIG. 4 illustrates a selective exposure of the photoresist layer 15 andthe protective layer 20 to form exposed regions 50, 50′ and unexposedregions 52, 52′. In some embodiments, the exposure to radiation iscarried out by placing the photoresist coated substrate in aphotolithography tool. The photolithography tool includes a photomask30, optics, an exposure radiation source to provide the radiation 45 forexposure, and a movable stage for supporting and moving the substrateunder the exposure radiation.

In some embodiments, the radiation source (not shown) supplies radiation45, such as ultraviolet light, to the protective layer 20 andphotoresist layer 15 in order to induce a reaction of the PACs, which inturn reacts with the polymer resin to chemically alter those regions ofthe photoresist layer to which the radiation 45 impinges. In someembodiments, the radiation is electromagnetic radiation, such as g-line(wavelength of about 436 nm), i-line (wavelength of about 365 nm),ultraviolet radiation, far ultraviolet radiation, extreme ultraviolet,electron beams, or the like. In some embodiments, the radiation sourceis selected from the group consisting of a mercury vapor lamp, xenonlamp, carbon arc lamp, a KrF excimer laser light (wavelength of 248 nm),an ArF excimer laser light (wavelength of 193 nm), an F₂ excimer laserlight (wavelength of 157 nm), or a CO₂ laser-excited Sn plasma (extremeultraviolet, wavelength of 13.5 nm).

In some embodiments, optics (not shown) are used in the photolithographytool to expand, reflect, or otherwise control the radiation before orafter the radiation 45 is patterned by the photomask 30. In someembodiments, the optics include one or more lenses, mirrors, filters,and combinations thereof to control the radiation 45 along its path.

In an embodiment, the patterned radiation 45 is extreme ultravioletlight having a 13.5 nm wavelength, the PAC is a photoacid generator, thegroup to be decomposed is a carboxylic acid group on the hydrocarbonstructure, and a cross linking agent is used. The patterned radiation 45impinges upon the photoacid generator, the photoacid generator absorbsthe impinging patterned radiation 45. This absorption initiates thephotoacid generator to generate a proton (e.g., a H⁺ atom) within thephotoresist layer 15. When the proton impacts the carboxylic acid groupon the hydrocarbon structure, the proton reacts with the carboxylic acidgroup, chemically altering the carboxylic acid group and altering theproperties of the polymer resin in general. The carboxylic acid groupthen reacts with the cross-linking agent to cross-link with otherpolymer resins within the exposed region of the photoresist layer 15.

In some embodiments, the exposure of the photoresist layer 15 uses animmersion lithography technique. In such a technique, an immersionmedium (not shown) is placed between the final optics and the protectivelayer, and the exposure radiation 45 passes through the immersionmedium.

In some embodiments, the thickness of the protective layer 20 issufficiently thin so that the protective layer 20 does not adverselyaffect the exposure of the photoresist layer 15 to the radiation 45.

After the protective layer 20 and the photoresist layer 15 has beenexposed to the exposure radiation 45, a post-exposure baking isperformed in some embodiments to assist in the generating, dispersing,and reacting of the acid/base/free radical generated from theimpingement of the radiation 45 upon the PACs during the exposure. Suchthermal assistance helps to create or enhance chemical reactions, whichgenerate chemical differences between the exposed region 50 and theunexposed region 52 within the photoresist layer 15. These chemicaldifferences also cause differences in the solubility between the exposedregion 50 and the unexposed region 52. In some embodiments, thepost-exposure baking occurs at temperatures ranging from about 50° C. toabout 160° C. for a period of between about 20 seconds and about 120seconds.

After the selective radiation exposure and/or the post-exposure bakeoperation, the PAC in the protective layer and photoresist produces anacid in some embodiments, and thus increases or decreases itssolubility. The solubility may be increased for positive resist (i.e.,the acid will cleave an acid cleavable polymer, resulting in the polymerbecoming more hydrophilic) and decreased for negative resist (i.e., theacid will catalyze an acid catalyzed crosslinkable polymer or cause apolymeric pinnacle to undergo pincaol rearrangement, resulting in thepolymer becoming more hydrophobic). Thus, when an aqueous-baseddeveloper is used, the developer will dissolve the exposed portions ofthe positive resist but not the exposed portions of the negative resist.

The inclusion of a cross-linking agent into the chemical reactions helpsthe components of the polymer resin (e.g., the individual polymers)react and bond with each other, increasing the molecular weight of thebonded polymer in some embodiments. In particular, an initial polymerhas a side chain with a carboxylic acid protected by one of the groupsto be removed/acid labile groups. The groups to be removed are removedin a de-protecting reaction, which is initiated by a proton H⁺ generatedby, e.g., the photoacid generator during either the exposure process orduring the post-exposure baking process. The H⁺ first removes the groupsto be removed/acid leaving groups and another hydrogen atom may replacethe removed structure to form a de-protected polymer. Once de-protected,a cross-linking reaction occurs between two separate de-protectedpolymers that have undergone the de-protecting reaction and thecross-linking agent in a cross-linking reaction in some embodiments. Inparticular, hydrogen atoms within the carboxylic groups formed by thede-protecting reaction are removed and the oxygen atoms react with andbond with the cross-linking agent. This bonding of the cross-linkingagent to two polymers bonds the two polymers not only to thecross-linking agent but also bonds the two polymers to each otherthrough the cross-linking agent, thereby forming a cross-linked polymer.

By increasing the molecular weight of the polymers through thecross-linking reaction, the new cross-linked polymer becomes lesssoluble in organic solvent negative resist developers.

Development is performed using a solvent. In some embodiments wherepositive tone development is desired, a positive tone developer such asa basic aqueous solution is used to remove regions 50 of the photoresistexposed to radiation. In some embodiments, the positive tone developer57 includes one or more selected from tetramethylammonium hydroxide(TMAH), tetrabutylammonium hydroxide, sodium hydroxide, potassiumhydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, sodiummetasilicate, aqueous ammonia, monomethylamine, dimethylamine,trimethylamine, monoethylamine, diethylamine, triethylamine,monoisopropylamine, diisopropylamine, triisopropylamine, monobutylamine,dibutylamine, monoethanolamine, diethanolamine, triethanolamine,dimethylaminoethanol, diethylaminoethanol, ammonia, caustic soda,caustic potash, sodium metasilicate, potassium metasilicate, sodiumcarbonate, tetraethylammonium hydroxide, combinations of these, or thelike.

In some embodiments where negative tone development is desired, anorganic solvent or critical fluid is used to remove the unexposedregions 52 of the photoresist. In some embodiments, the negative tonedeveloper 57 includes one or more selected from hexane, heptane, octane,toluene, xylene, dichloromethane, chloroform, carbon tetrachloride,trichloroethylene, and like hydrocarbon solvents; critical carbondioxide, methanol, ethanol, propanol, butanol, and like alcoholsolvents; diethyl ether, dipropyl ether, dibutyl ether, ethyl vinylether, dioxane, propylene oxide, tetrahydrofuran, cellosolve, methylcellosolve, butyl cellosolve, methyl carbitol, diethylene glycolmonoethyl ether and like ether solvents; acetone, methyl ethyl ketone,methyl isobutyl ketone, isophorone, cyclohexanone and like ketonesolvents; methyl acetate, ethyl acetate, propyl acetate, butyl acetateand like ester solvents; pyridine, formamide, and N,N-dimethyl formamideor the like.

In some embodiments, the developer 57 is applied to the protective layer20 and photoresist layer 15 using a spin-on process. In the spin-onprocess, the developer 57 is applied to the protective layer 20 andphotoresist layer 15 by a dispenser 62 from above while the coatedsubstrate is rotated, as shown in FIG. 5. The developer 57 is selectedso that it develops both the protective layer 20 and the photoresistlayer 15 in some embodiments. In the case of a positive resist, theexposed region 50 of the photoresist layer is removed, and in the caseof a negative resist the unexposed regions 52 of the photoresist layerare removed. In some embodiments, the developer 57 is supplied at a rateof between about 5 ml/min and about 800 ml/min, while the coatedsubstrate 10 is rotated at a speed of between about 100 rpm and about2000 rpm. In some embodiments, the developer is at a temperature ofbetween about 10° C. and about 80° C. The development operationcontinues for between about 30 seconds to about 10 minutes in someembodiments.

In some embodiments, the photoresist developers 57 dissolve thecross-linked, radiation-exposed portions 50 of the photoresist layer 15or protective layer 20. Such a developer is a tone-reversal developer.In some embodiments, the tone-reversal developer 57 includes a majorsolvent, an acid or a base, and a chelate. In some embodiments, theconcentration of the major solvent is from about 60 wt. % to about 99wt. % based on the total weight of the photoresist developer. The acidor base concentration is from about 0.001 wt. % to about 20 wt. % basedon the total weight of the photoresist developer. In certainembodiments, the acid or base concentration in the developer is fromabout 0.01 wt. % to about 15 wt. % based on the total weight of thephotoresist developer. The chelate concentration is from about 0.001 wt.% to about 20 wt. % of the total weight of the photoresist developer. Incertain embodiments, the concentration of the chelate ranges from about0.01 wt. % to about 15 wt. % based on the total weight of thephotoresist developer.

In some embodiments, the major solvent has Hansen solubility parametersof 15<δ_(d)<25, 10<δ_(p)<25, and 6<δ_(h)<30. The units of the Hansensolubility parameters are (Joules/cm³)^(1/2) or, equivalently, MPa^(1/2)and are based on the idea that one molecule is defined as being likeanother if it bonds to itself in a similar way. δ_(d) is the energy fromdispersion forces between molecules. δ_(p) is the energy from dipolarintermolecular force between the molecules. δ_(h) is the energy fromhydrogen bonds between molecules. The three parameters, δ_(d), δ_(p),and δ_(h), can be considered as coordinates for a point in threedimensions, known as the Hansen space. The nearer two molecules are inHansen space, the more likely they are to dissolve into each other.

Solvents having the desired Hansen solubility parameters includedimethyl sulfoxide, acetone, ethylene glycol, methanol, ethanol,propanol, propanediol, water, 4-methyl-2-pentanone, hydrogen peroxide,isopropanol, and butyldiglycol.

In some embodiments, the acid has an acid dissociation constant, pK_(a),of −15<pK_(a)<4. In some embodiments, the base has a pK_(a) of40>pK_(a)>9.5. The acid dissociation constant, pK_(a), is thelogarithmic constant of the acid dissociation constant K_(a). K_(a) is aquantitative measure of the strength of an acid in solution. K_(a) isthe equilibrium constant for the dissociation of a generic acidaccording to the equation HA+H₂O↔A⁻+H₃O⁺, where HA dissociates into itsconjugate base, A⁻, and a hydrogen ion which combines with a watermolecule to form a hydronium ion. The dissociation constant can beexpressed as a ratio of the equilibrium concentrations:

$K_{a} = {\frac{\left\lbrack A^{-} \right\rbrack\left\lbrack {H_{3}O^{+}} \right\rbrack}{\lbrack{HA}\rbrack\left\lbrack {H_{2}O} \right\rbrack}.}$

In most cases, the amount of water is constant and the equation can besimplified to HA↔A⁻+H⁺, and

$K_{a} = {\frac{\left\lbrack A^{-} \right\rbrack\left\lbrack H^{+} \right\rbrack}{\lbrack{HA}\rbrack}.}$

The logarithmic constant, pK_(a) is related to K_(a) by the equationpK_(a)=−log₁₀(K_(a)). The lower the value of pK_(a) the stronger theacid. Conversely, the higher the value of pK_(a) the stronger the base.

In some embodiments, suitable acids for the photoresist developer 57include an organic acid selected from the group consisting ofethanedioic acid, methanoic acid, 2-hydroxypropanoic acid,2-hydroxybutanedioic acid, citric acid, uric acid,trifluoromethanesulfonic acid, benzenesulfonic acid, ethanesulfonicacid, methanesulfonic acid, oxalic acid, maleic acid, carbonic acid,oxoethanoic acid, 2-hydroxyethanoic acid, propanedioic acid, butanedioicacid, 3-oxobutanoic acid, hydroxylamine-o-sulfonic acid,formamidinesulfinic acid, methylsulfamic acid, sulfoacetic acid,1,1,2,2-tetrafluoroethanesulfonic acid, 1,3-propanedisulfonic acid,nonafluorobutane-1-sulfonic acid, 5-sulfosalicylic acid, andcombinations thereof. In some embodiments, the acid is an inorganic acidselected from the group consisting of nitric acid, sulfuric acid,hydrochloric acid, and combinations thereof.

In some embodiments, suitable bases for the photoresist developer 57include an organic base selected from the group consisting ofmonoethanolamine, monoisopropanolamine, 2-amino-2-methyl-1-propanol,1H-benzotriazole, 1,2,4-triazole, 1,8-diazabicycloundec-7-ene,tetrabutylammonium hydroxide, tetramethylammonium hydroxide, ammoniumhydroxide, ammonium sulfamate, ammonium carbamate, tetraethylammoniumhydroxide, tetrapropylammonium hydroxide, and combinations thereof.

In some embodiments, the chelate is selected from the group consistingof ethylenediaminetetraacetic acid (EDTA),ethylenediamine-N,N′-disuccinic acid (EDDS),diethylenetriaminepentaacetic acid (DTPA), polyaspartic acid,trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid monohydrate,ethylenediamine, and combinations thereof, or the like.

In an embodiment, the photoresist developer 57 includes an additionalsolvent. In some embodiments, the additional solvent includes water;hexane, heptane, octane, toluene, xylene, dichloromethane, chloroform,carbon tetrachloride, trichloroethylene, and like hydrocarbon solvents;critical carbon dioxide, methanol, ethanol, propanol, butanol, and likealcohol solvents; diethyl ether, dipropyl ether, dibutyl ether, ethylvinyl ether, dioxane, propylene oxide, tetrahydrofuran, cellosolve,methyl cellosolve, butyl cellosolve, methyl carbitol, diethylene glycolmonoethyl ether and like ether solvents; acetone, methyl ethyl ketone,methyl isobutyl ketone, isophorone, cyclohexanone and like ketonesolvents; methyl acetate, ethyl acetate, propyl acetate, butyl acetateand like ester solvents; pyridine, formamide, and N,N-dimethyl formamideor the like. In an embodiment, the concentration of the additionalsolvent is from about 1 wt. % to about 40 wt. % based on the totalweight of the developer.

In some embodiments, the photoresist developer 57 includes hydrogenperoxide in a concentration of up to about 10 wt. % based on the totalweight of the developer.

In some embodiments, the photoresist developer 57 includes up to about 1wt. % of a surfactant to increase the solubility and reduce the surfacetension on the substrate. In some embodiments, the surfactant isselected from the group consisting of alkylbenzenesulfonates, ligninsulfonates, fatty alcohol ethoxylates, and alkylphenol ethoxylates. Insome embodiments, the surfactant is selected from the group consistingof sodium stearate, 4-(5-dodecyl) benzenesulfonate, ammonium laurylsulfate, sodium lauryl sulfate, sodium laureth sulfate, sodium myrethsulfate, dioctyl sodium sulfosuccinate, perfluorooctanesulfonate,perfluorobutanesulfonate, alkyl-aryl ether phosphate, alkyl etherphosphates, sodium lauroyl sarcosinate, perfluoronononanoate,perfluorooctanoate, octenidine dihydrochloride, cetrimonium bromide,cetylpyridinium chloride, benzalkonium chloride, benzethonium chloride,dimethyldioctadecylammonium chloride, dioctadecyldimethylammoniumbromide, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate,cocamidopropyl hydroxysultaine, cocamidopropyl betaine,phospholipidsphosphatidylserine, phosphatidylethanolamine,phosphatidylcholine, sphingomyelins, octaethylene glycol monodecylether, pentaethylene glycol monodecyl ether, polyethoxylated tallowamine, cocamide monoethanolamine, cocamide diethanolamine, glycerolmonostearate, glycerol monolaurate, sorbitan monolaurate, sorbitanmonostearate, sorbitan tristearate, and combinations thereof.

In some embodiments, the protective layer 20 is a positive tone materialand is developed with a positive tone developer, and the photoresistlayer 15 is a negative tone resist and is developed with a tone-reversaldeveloper.

While the spin-on operation is one suitable method for developing thephotoresist layer 15 after exposure, it is intended to be illustrativeand is not intended to limit the embodiment. Rather, any suitabledevelopment operations, including dip processes, puddle processes, andspray-on methods, may alternatively be used. All such developmentoperations are included within the scope of the embodiments.

In some embodiments the exposed portions 50′ of the protective layerremain on the photoresist layer 15 and the unexposed portions areremoved during development as shown in FIG. 6A. In other embodiments,the exposed portions 50′ of the protective layer are removed duringdevelopment and the unexposed portions 52′ remain on the photoresistlayer 50 after development. In some embodiments, the exposed portions50′ of the protective layer 20 remain on the exposed portions of thephotoresist layer 50 after development, as shown in FIG. 6B. Theremaining portions 50′ of the protective layer are subsequently removedusing a suitable stripper after developing the photoresist layer 15.Upon development of the photoresist layer 15 the layer to be patternedor substrate 10 is exposed, as shown in FIG. 6B. In some embodiments, afirst developer is used to develop the protective layer 20 and then asecond, different developer is used to develop the photoresist layer 15.

During the development process, the developer 57 develops the protectivelayer 20 and radiation unexposed regions 52 of the cross-linked negativeresist in some embodiments, exposing the surface of the substrate 10, asshown in FIG. 7, and leaving behind well-defined exposed photoresistregions 50, in some embodiments.

After the developing operation S150, remaining developer is removed fromthe patterned photoresist covered substrate. The remaining developer isremoved using a spin-dry process in some embodiments, although anysuitable removal technique may be used. After the photoresist layer 15is developed, and the remaining developer is removed, additionalprocessing is performed while the patterned photoresist layer 50 is inplace. For example, an etching operation, using dry or wet etching, isperformed in some embodiments, to transfer the pattern 55 of thephotoresist layer 52 to the underlying substrate 10, forming recesses55′ as shown in FIG. 8. The substrate 10 has a different etch resistancethan the photoresist layer 15. In some embodiments, the etchant is moreselective to the substrate 10 than the photoresist layer 15.

In some embodiments, the substrate 10 and the photoresist layer 15contain at least one etching resistance molecule. In some embodiments,the etching resistant molecule includes a molecule having a low Onishinumber structure, a double bond, a triple bond, silicon, siliconnitride, titanium, titanium nitride, aluminum, aluminum oxide, siliconoxynitride, combinations thereof, or the like.

In some embodiments, a layer to be patterned 60 is disposed over thesubstrate prior to forming the photoresist layer 15, as shown in FIG.12. In some embodiments, the layer to be patterned 60 is a metallizationlayer or a dielectric layer, such as a passivation layer, disposed overa metallization layer. In embodiments where the layer to be patterned 60is a metallization layer, the layer to be patterned 60 is formed of aconductive material using metallization processes, and metal depositiontechniques, including chemical vapor deposition, atomic layerdeposition, and physical vapor deposition (sputtering). Likewise, if thelayer to be patterned 60 is a dielectric layer, the layer to bepatterned 60 is formed by dielectric layer formation techniques,including thermal oxidation, chemical vapor deposition, atomic layerdeposition, and physical vapor deposition.

The protective layer 20 and the photoresist layer 15 are subsequentlyselectively exposed to actinic radiation 45 to form exposed regions 50and unexposed regions 52 in the photoresist layer, as shown in FIG. 13,and described herein in relation to FIG. 4. In these embodiments, thephotoresist is a positive photoresist, wherein the solubility of thephotoresist polymer in the developer 57 increases in the exposed regions50.

As shown in FIG. 14, the exposed photoresist and protective layerregions 50, 50′ are developed by dispensing developer 57 from adispenser 62 to form a pattern of photoresist openings 55, as shown inFIG. 15. The protective layer is removed by a suitable stripper solventand the exposed photoresist regions are removed by the developer 57 inthis embodiment. In some embodiments, the exposed portions 50′ of theprotective layer 20 are removed by a first developer and then theexposed portions 50 of the photoresist layer are removed by a second,different developer, such as a tone-reversal developer as describedherein.

Then as shown in FIG. 16, the pattern 55 in the photoresist layer 15 istransferred to the layer to be patterned 60 using an etching operationand the photoresist layer is removed, as explained with reference toFIG. 8 to form pattern 55″ in the layer to be patterned 60.

In some embodiments, the selective exposure of the photoresist layer 15and the protective layer 20 to form exposed regions 50, 50′ andunexposed regions 52, 52′ is performed using extreme ultravioletlithography. In an extreme ultraviolet lithography operation, areflective photomask 65 is used to form the patterned exposure light, asshown in FIG. 17. The reflective photomask 65 includes a low thermalexpansion glass substrate 70, on which a reflective multilayer 75 of Siand Mo is formed. A capping layer 80 and absorber layer 85 are formed onthe reflective multilayer 75. A rear conductive layer 90 is formed onthe back side of the low thermal expansion substrate 70. In extremeultraviolet lithography, extreme ultraviolet radiation 95 is directedtowards the reflective photomask 65 at an incident angle of about 6°. Aportion 97 of the extreme ultraviolet radiation is reflected by theSi/Mo multilayer 75 towards the photoresist coated substrate 10, whilethe portion of the extreme ultraviolet radiation incident upon theabsorber 85 is absorbed by the photomask. In some embodiments,additional optics, including mirrors are between the reflectivephotomask 65 and the photoresist coated substrate.

The novel protective layer and photolithography techniques according tothe present disclosure provide improved critical dimension variation andreduces defects. The protective layer prevents the absorption of waterand ammonia and particle contamination of the photoresist duringsemiconductor device processing. Semiconductor devices formed accordingto the present disclosure have improved critical dimension stabilitycontrol. Use of the disclosed protective layer allows the criticaldimension variation to be controlled within a 20% variation. In someembodiments, the use of the disclosed protective layer provides a 5-30%improvement in the critical dimension variation over other methods.Further, use of the disclosed protective layer provides up to a 10%reduction in defects than conventional techniques. In addition, use ofthe disclosed protective layer reduces environmental contamination andprovides up to a 5% reduction in exposure dose required to sufficientlyexpose the photoresist.

An embodiment of the disclosure includes a method of forming aphotoresist pattern. The method includes forming a protective layer overa photoresist layer formed on a substrate. The protective layer and thephotoresist layer are selectively exposed to actinic radiation. Theprotective layer and the photoresist layer are developed to form apattern in the protective layer and the photoresist layer, and theprotective layer is removed. The protective layer includes a polymerhaving pendant fluorocarbon groups and pendant acid leaving groups. Inan embodiment, material forming the protective layer is mixed withphotoresist material to form a mixture, and the mixture is disposed overthe substrate. In an embodiment, the substrate with the mixture disposedthereon is rotated, and the protective layer separates from the mixtureduring the rotating and forms the protective layer over the photoresistlayer. In an embodiment, the photoresist layer is formed on thesubstrate and the photoresist layer is heated prior to forming theprotective layer. In an embodiment, the photoresist layer includes metaloxide nanoparticles. In an embodiment, the actinic radiation is extremeultraviolet radiation. In an embodiment, photoresist layer andprotective layer are heated after selectively exposing the photoresistlayer. In an embodiment, the protective layer has a thickness rangingfrom 0.1 nm to 20 nm. In an embodiment, the contact angle of theprotective layer to water is greater than 75°.

Another embodiment of the disclosure is a method of fabricating asemiconductor device. The method includes supplying a photoresistcomposition to a substrate surface to form a photoresist layer over thesubstrate. A protective layer is formed over the photoresist layer. Theprotective layer and the photoresist layer are patternwise exposed toextreme ultraviolet radiation to form a latent pattern in the protectivelayer and the photoresist layer. The protective layer and thephotoresist layer are heated after the patternwise exposing. Theprotective layer and the photoresist layer are developed. Thephotoresist layer includes a metal oxide, and the protective layerincludes a polymer having pendant fluorocarbon groups and pendant acidleaving groups. In an embodiment, the supplying a photoresistcomposition to the substrate surface, includes mixing the polymer havingthe pendant fluorocarbon and acid leaving groups with the photoresistcomposition to form a mixture, and supplying the mixture to thesubstrate surface. In an embodiment, the protective layer is formed byspinning the substrate with the mixture disposed thereon, therebycausing the polymer having pendant fluorocarbon and acid leaving groupsto separate from the mixture and form the protective layer over thephotoresist layer.

Another embodiment of the disclosure is a photoresist compositionincluding a photoresist material, and a polymer having pendantfluorocarbon and acid leaving pendant groups. In an embodiment, thephotoresist material includes metal oxide nanoparticles. In anembodiment, a main chain of the polymer having the pendant fluorocarbonacid leaving groups is a polyhydroxystyrene, a polyacrylate, or apolymer formed from a 1 to 10 carbon monomer. In an embodiment, thepolymer having the pendant fluorocarbon and acid leaving groups includesfrom 30 wt. % to 70 wt. % of the pendant fluorocarbon groups and from 30wt. % to 70 wt. % of the acid leaving groups based on the total weightof the polymer having the pendant fluorocarbon groups and pendant acidleaving groups. In an embodiment, the pendant fluorocarbon groups areattached to a polymer main chain via a linking unit of at least oneselected from the group consisting of 1-9 carbon unbranched, branched,cyclic, noncylic, saturated, or unsaturated hydrocarbon with optionalhalogen substituents; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—;—C(═O)N—; —SO₂O—; —SO₂S—; —SO—; —SO₂—; and —C(═O)—. In an embodiment,the pendant fluorocarbon group is selected from the group consisting ofC_(x)F_(y), where 1≤x≤9 and 3≤y≤12; and —(C(CF₃)₂OH). In an embodiment,the pendant acid leaving group is selected from the group consisting of

In an embodiment, the photoresist composition includes a photoacidgenerator.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A photoresist composition, comprising: a photoresist material; and a polymer having pendant fluorocarbon groups and pendant acid leaving groups.
 2. The photoresist composition of claim 1, wherein the photoresist material comprises metal oxide nanoparticles.
 3. The photoresist composition of claim 1, wherein the polymer having pendant fluorocarbon groups and pendant acid leaving groups comprises from 0.1 wt. % to 10 wt. % of one or more polar functional groups selected from the group consisting —OH, —NH₃, —NH₂, and —SO₃ based on the total weight of the polymer having the pendant fluorocarbon and acid leaving groups.
 4. The photoresist composition of claim 1, wherein the polymer having the pendant fluorocarbon and acid leaving groups comprises from 30 wt. % to 70 wt. % of the pendant fluorocarbon pendant and from 30 wt. % to 70 wt. % of the acid leaving groups based on the total weight of the polymer having the pendant fluorocarbon and acid leaving groups.
 5. The photoresist composition of claim 1, wherein the pendant fluorocarbon groups are attached to a polymer main chain via a linking unit of at least one selected from the group consisting of 1-9 carbon unbranched, branched, cyclic, noncylic, saturated, or unsaturated hydrocarbon with optional halogen substituents; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—; —C(═O)N—; —SO₂O—; —SO₂S—; —SO—; —SO₂—; and —C(═O)—.
 6. The photoresist composition of claim 1, wherein the pendant fluorocarbon group is selected from the group consisting of C_(x)F_(y), where 1≤x≤9 and 3≤y≤12; and —(C(CF₃)₂OH)—.
 7. The photoresist composition of claim 1, wherein the pendant acid leaving group is selected from the group consisting of


8. The photoresist composition of claim 1, further comprising a photoacid generator.
 9. A photoresist composition, comprising: a protective polymer having pendant fluorocarbon groups and pendant acid leaving groups; a polymer resin having pendant acid leaving groups; and a photoactive compound.
 10. The photoresist composition of claim 9, wherein the protective polymer having pendant fluorocarbon groups and pendant acid leaving groups comprises from 0.1 wt. % to 10 wt. % of one or more polar functional groups selected from the group consisting —OH, —NH₃, —NH₂, and —SO₃ based on the total weight of the polymer having the pendant fluorocarbon and acid leaving groups.
 11. The photoresist composition of claim 9, wherein the protective polymer having the pendant fluorocarbon and acid leaving groups comprises from 30 wt. % to 70 wt. % of the pendant fluorocarbon pendant and from 30 wt. % to 70 wt. % of the acid leaving groups based on the total weight of the polymer having the pendant fluorocarbon and acid leaving groups.
 12. The photoresist composition of claim 9, wherein the pendant fluorocarbon groups are attached to a polymer main chain via a linking unit of at least one selected from the group consisting of 1-9 carbon unbranched, branched, cyclic, noncylic, saturated, or unsaturated hydrocarbon with optional halogen substituents; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—; —C(═O)N—; —SO₂O—; —SO₂S—; —SO—; —SO₂—; and —C(═O)—.
 13. The photoresist composition of claim 9, wherein the pendant fluorocarbon group is selected from the group consisting of C_(x)F_(y), where 1≤x≤9 and 3≤y≤12; and —(C(CF₃)₂OH)—.
 14. The photoresist composition of claim 9, wherein the pendant acid leaving group is selected from the group consisting of


15. A photoresist composition, comprising: a first polymer having pendant fluorocarbon groups and first pendant acid labile groups; a second polymer having second pendant acid labile groups; metal oxide nanoparticles; a photoacid generator; and a solvent.
 16. The photoresist composition of claim 15, wherein the pendant fluorocarbon groups are selected from the group consisting of C_(x)F_(y), where 1≤x≤9 and 3≤y≤12; and —(C(CF₃)₂OH)—.
 17. The photoresist composition of claim 16, wherein the pendant fluorocarbon groups are attached to a polymer main chain via a linking unit of at least one selected from the group consisting of 1-9 carbon unbranched, branched, cyclic, noncylic, saturated, or unsaturated hydrocarbon with optional halogen substituents; —S—; —P—; —P(O₂); —C(═O)S—; —C(═O)O—; —O—; —N—; —C(═O)N—; —SO₂O—; —SO₂S—; —SO—; —SO₂—; and —C(═O)—.
 18. The photoresist composition of claim 15, wherein the first pendant acid labile groups are selected from the group consisting of


19. The photoresist composition of claim 15, wherein the second polymer includes a repeating unit that forms a skeletal backbone of the second polymer, and the repeating unit is one or more of a acrylic ester, a methacrylic ester, a crotonic ester, a vinyl ester, a maleic diester, a fumaric diester, an itaconic diester, a (meth)acrylonitrile, a (meth)acrylamide, a styrene, a vinyl ether.
 20. The photoresist composition of claim 15, wherein the polymer having the pendant fluorocarbon and first acid labile groups comprises from 30 wt. % to 70 wt. % of the pendant fluorocarbon pendant and from 30 wt. % to 70 wt. % of the acid labile groups based on the total weight of the polymer having the pendant fluorocarbon and acid labile groups. 